How to Remove Mildew Off Wood

Mildew is a type of mold that thrives in warm, humid climates and grows readily on damp wood. It can sometimes be very difficult to remove and can even grow under layers of paint. A variety of chemicals are available to kill and remove mildew stains from wood including trisodium phosphate, bleach and oxalic acid.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Trisodium phosphate
• Bucket
• Scrub brush
• Sponge
• Mildew-resistant paint
• Paint remover
• Bleach
• Oxalic acid

1. Increase the temperature and air circulation around the wood surface. Damp wood is a breeding ground for mildew. Drying the wood will make the mildew easier to remove and hinder future mildew growth.

2. Mix 8 to 10 tablespoons of trisodium phosphate in a bucket with 1 gallon of water. Dip the scrub brush into the solution and scrub the mildew off of the wood. For soft or delicate wood surfaces, use a sponge to scrub.

3. Rinse the solution from the wood with cold water and replace in the heated and ventilated area. Allow the wood to dry thoroughly. Coat the wood with a mildew-resistant paint to prevent future mildew growth. Follow the directions on the paint that correlate with the type of wood.

4. Remove mold that has grown under paint by using a paint remover to remove the coat. Create a solution of 8 tablespoons of trisodium phosphate, 1 cup of bleach and 1 gallon of water in a bucket. Scrub well using a sponge or scrub brush.

5. Remove extremely tough mildew stains with oxalic acid. Mix three tablespoons of the acid with one pint of water in a clean bucket. Scrub the stain well and rinse thoroughly with cold water. Allow it to dry in a well-heated and ventilated room before applying paint or finish.

Tips & Warnings

• Oxalic acid and trisodium phosphate can be purchased from janitorial stores, as well as some specialized hardware and paint stores. Washing soda, quaternary disinfectant, or pentachlorophenate can be used in place of trisodium phosphate.
• When handling bleach, always wear a particle mask and rubber gloves. Bleach can be very dangerous and should be handled with the utmost care. Never inhale bleach. Oxalic acid is poisonous and shouldn't be inhaled or handled with bare hands. Always wear rubber gloves and a particle mask. Wash hands thoroughly after handling. Dispose of the mixture in a landfill or other certified dump areas.